Tree traversal Practice Question

Duration: 2 min

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Module outline

  1. Communication Round: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Direct and Indirect Speech, Active Passive Voice (Voice), Verbal Analogy (Word Based Analogy), Articles, Preposition, Conjunction, Sentence Construction, English Writing Ability, Communication Assessment
  2. Quantitative Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Age Problems, Pipe and Cistern, Probability, Profit and Loss, Simple Interest and Compound Interest, Algebra
  3. Analytical and Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Puzzle Solving (Puzzles), Syllogisms, Seating Arrangements, Calendar, Clock, Blood Relations, Cubes & Dices, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning)
  4. Cognizant Gaming Aptitude: Gamified / Game Based Aptitude
  5. Java (Cluster 1): Java
  6. ANSI SQL MySQL (Cluster 1,2,3): SQL
  7. HTML, CSS, JavaScript (Cluster 1,3): HTML, CSS, JavaScript
  8. Python (Cluster 2): Python for Placements by Yash Sir
  9. Cloud Fundamentals (Cluster 2): Emerging Tech Trends
  10. C# (Cluster 3): C#
  11. OOPs: Object Oriented Programming (OOPS)
  12. Technical Assessment (Coding): Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Pseudo Codes
  13. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  15. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  16. Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video segment focuses on solving a binary tree traversal problem commonly found in computer science exams. The instructor presents a specific question asking for the post-order traversal given the in-order sequence "d b e a f c g" and the pre-order sequence "a b d e c f g". He begins by identifying the root of the tree from the first element of the pre-order traversal, which is 'a'. He then locates 'a' in the in-order sequence to divide the tree into left and right subtrees. The left subtree contains nodes "d b e" and the right subtree contains "f c g". He proceeds to recursively apply this logic to construct the full tree structure on the whiteboard. Finally, he performs a post-order traversal (Left-Right-Root) on the constructed tree to determine the final sequence, writing it down for verification against the multiple-choice options. He carefully checks each node's position to ensure the traversal order is correct.

Chapters

  1. 0:00 – 1:36 00:00-01:36

    The video opens with the problem statement displayed on screen, showing in-order "d b e a f c g" and pre-order "a b d e c f g" sequences. The instructor identifies 'a' as the root node from the pre-order list and marks it in the in-order list to split nodes into left "d b e" and right "f c g" groups. He explains that 'b' is the root of the left subtree and 'c' is the root of the right subtree. He draws the tree structure on the whiteboard, placing 'a' at the top with 'b' and 'c' as children, and fills in leaves 'd', 'e', 'f', and 'g'. Finally, he writes the post-order sequence "d e b f g c a" at the bottom and underlines option (d), noting a discrepancy between his written result and the printed options.

The video effectively demonstrates the recursive algorithm for reconstructing a binary tree from its traversals. By alternating between pre-order (to find roots) and in-order (to define subtrees), one can uniquely determine the tree structure. The final post-order traversal is simply the reverse of the construction process, visiting children before parents. This method is crucial for understanding tree data structures and their properties in computer science exams, highlighting the relationship between different traversal orders. It shows how a single tree can be represented by multiple sequences.

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